Slip mechanism



Dec. 27, .1-932. N. yv. wxcKERsHAM Attorneys SLIP MECHANISM .lll/VIII;

'414444 l finiti fff Filed March 28, 1932 rama.: M127, .una`

UNITED STATES PATENT OFFICE 2: 1 OF LOS ANGELES, CALIFORNIA, ASSIGNOB '.lO PERKINS OI' LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA SL11 armament application mea umn afa-1932. semi no. 001,561.

This invention relates to slip mechanisms for locking various devices in a well casmg, and particularly to a slip mechanism for use with a well cleaner. l

A broad object of the Ainvention is to prevent premature setting of slips in a slip mechanism while the latter is being run intothe casing. Y

Another object is to increase the reliability and simplify the construction of a slip mechanism. Y 0

In my copending application, Serlal No.

550,682, filed July 14, 1931, on oil well clean-- ing device there isdisclosed a wellv cleaner incorporating a-sl1p mechanism comprising a slip' expander mounted upon a hollow sleeve;

slips positioned about the expander; an up-4 per collar slidable upon the sleeve below the.

expander, to which collarthe slips are mechanically linked; a lower) collar also slldably positioned upon the sleeve below the upper collar and joined thereto by'a plurahty of springs which are outwardly bowed at their centers to frictionally engage a well cas,- ing. A locking mechanism is provided for maintaining the lower collar near the lower end of the sleeve to retract the shps to the lower end of the slip expander, (in which position the slips are contracted) whllethe mechanism is being lowered into the casing.

The structure described functions very satisfactorily in straight uniform casing but 1f there is 'a bend or constriction in the casing one or more of the outwardly bowed casingengaging'springs may be forced inwardly by therv casing, thus straightening 1t and lengthening it and forcing the upper collar and slips upwardly. As a result of this upward movement the slips may be expanded sufciently to cause one or more of them to engage the casing, and thus lock the device to the casing.

In accordance with the present invention the aforementioned objectionable characteristie of a slip mechanism constructed as described is eliminated by locking the upper collar instead of the lower collar to the sleeve, thus rigidly anchoring the slips in their lowermo'st'position on the slip expander independently of the bowed casing-engaging springs.

The invention will now be described in detail with reference to the drawing, in which Figure 1 is an elevational view of the slip mechanism in a well casing with the slips retracted;

Figure 2 is an elevational sectional view of the device;

, Figure 3 is a detail, sectional view showing the device with the slips expanded; and

Figure 4 is a developed view showing the complete surface outline of the upper collar and slot therein. v f

Referring to the drawing, my device com prises a central shaft 1 upon which there is slidably mounted a sleeve 4, upon which is rigidly mounted a slip expander 2, a slip link collar 3. The upper end of shaft 1 is threaded into a coupling union 5 which in turn may be threaded to any tool which it is desired to use in connection with the slip mechanism,

' it being understood that the tool in turn is The slip expander 2 comprises a member bored to receive the shaft 1 and provided with slip seats7 on its outer face. Four slip seats have been shown in the drawing, butany desired number may be used. Each slip seat extends upwardly and outwardly and carries a slip 8 which is slidable in the seat 7 from a lower position as shown in Figures 1 and 2 in which the sli s` are retracted out of engagement with t e casing, to an upper position as shown i Figure 3 in which they are wedged into contact with the casing. Each slip is provided with teeth as shown, to better engage the casing. A

Each slip 8 is pivotally secured by a pin 9 to a link 10 which extends downwardly below the slip and is pivotally connected to a lower edge of the collar 11 at its lower end as clearly shown in Figure 4. A ypin 16 extends radially from the wall of sleeve 4 and is engageable with the slot 14 byrotating the sleeve relative to the collar 11. When the pin 16 is positioned in the end 15 of slot 14 it serves to retain the collar 11 in its lower position, in which the slips 8 are retracted.

It is necessary to maintain the slips in retracted position as shown in Figure 1 while the device is being run into a casing and to prevent the pin 16 from being moved out of the slot 14 by `joltin or unintentional rota-y tion of the slips, a co lar 17 is rigidly secured to the sleeve 4 a short distance below the pin 16 and a spiral spring 18, togetherv with a.`

washer 19,'positioned about the sleeve 4 between the collar 17 and the pin 16. With this construction it will be observed from an inspection of Figure 1 that when the pin 16 is positioned in the depressed end 15l of the slot 14 the spring 18 is compressed betweenl the upper edge of fixed collar 17 and the lower edge of the locking' collar 11. As a result, the spring maintains a pressure between the in 16 projecting from sleeve 4 and the notc ed end 15 of slot 14, thus preventing the pin from being 'accidentally dislodged Vfrom members 21 which are provided to frictionalthe end of the slot.

Slidably mounted upon the sleeve 4 is another collar 20 which. is connected to the locking collar 11 by a plurality of bowed spring ly engage with the well casing at all times to provide a tdesired amount of friction between the upper collar 11 and the casing.

The lower end of sleeve 4 is provided with a head 22 which'is rigidly attached to the sleeve. The lower edge of this head 22 is half cutaway to provide shoulders 23 engeable'with similar juxtaposed shoulders 24 on the head 6, which is rigidly attached to the lower end of the central tubular member 1. The purpose of these shoulders will be made clear from a description of the operation of the device.

Assume that the coupling 5 at the upper end of tube 1 is secured to/a wellcleaner or some other tool that is tofbe lowered into a well, and that the upper end of the packer in turn is 'secured to a string of tubing and that the entire assembly comprisingithe slip mechanism and the well cleaner or other tool has been lowered into a casing to a where it is desired to lock the assembly to the insertion of the sli' casing. Previous to'the pin 16 woul mechanism into the casing the -downward within point be turned into the' slot 14 and locked in the end 15 thereof b the spring 18 bearin be# tween collar' 17 -ed to the sleeve 4 an the lower'edge of the lock collar 17. This retains the slips in their lowermost position with respect to the expander Ahea'd 2 so that the slips are retained in retracted position as shown. device pass through bent or vdistorted casing while bein lowered into the well, any inward disp acernent of the bowed spring members21 will merel" result in forcing the lower collarf20 down a ong sleeve 4, since the upper rlock collar 17 is securely retained against upward movement by the pin 16.

device is being lowered into the well the friction between tlie bowed springs 21 and the casing constitutes suicient dra to maintain the head2 and the sleeve 4 on t e upper end of the shaft 1 so-that the expander 2 abuts gatnst the lower end oftl'ie coupling membeen reache and it is ldesired to set the slip mechanism,.the tubing string is elevated, a short distance, thus sliding shaft 1 upwardly .through the sleeve 4 -until the head 6' on the end of shaft 1 abuts against the/head 22 on .the lower end of sleeve 4. The tubing string is then rotated to the right while at the same It will be observed-that should the ea It-should be further noted that 'while the When the roper position in the casing has I time it is being maintained in a slight upward movement until the head 6 is so ositioned as to engage the faces 24 withthe aces 23 on head 22. Thereafter continued rotal tion to the right of the striiig of tubing and shaft-1 will rotate sleeve 4 and the pin 16 f projectin restraine from rotation since it is secured to the upper ends of the bowed spring mem bers 21 which are in frictional engagement with the casing. Therefore the pin 16 will be rotated out of engagement wit slot 14.

After thetubing string has been rotated to the right suiciently to release pin 16 from and the string of tubing in the casing until the 'couthe top of the expander head casing through the bowed springs 21, it will tend to remain stationaryl in the casing and will tend tomaintain the slips 8 stationary since they will therefore be forced downward with re s t tothe slips8, ywhich will ride up on t eir seats 7 until they touch the casihg and.

ther with the sleeve y4,--

are attached to'collar 11 by thelinks 10 and collar 3. The expander head 2 therefrom; collar 11 however, is

sleeve 4 and is frictionally engaged to the i lock therewith. The locking of the slips with v the casing securely anchors the entire assembllt; the casing.

en it is desired towithdrawthe `assem-4 1.10'. engagement with slot 14 as described, the

bly, the slips are released by lifting the strin'g of tubing and the shaft 1 until the head 6 on the lower end of shaft 1 strikes the head 22 on the lower end of sleeve 4; thereafter further elevation of the shaft 1 elevates the sleeve 4 and the expander head 2 andthe slips, which are frictionally engaged with the casing, slide downward along their seats 7 until they are disengaged from the casing. The elevation of sleeve 4 will be continued until the pin 16 strikes the lower end of collar 11. -The string of tubing and shaft 1 will then be rotated to the left, while still being elevated, until the faces 24 on head 6 engage with faces 23 on the head 22 and rotate the sleeve 4. Since rotation of the collar l1 is resisted by the frictional engagement of the bowed springs-21 with the casing, pin 16 projecting from sleeve 4 will be rotated with respect to collar 11 and will engage with the slot 14 as shown in Figure l." Thereafter, the entire assembly may be Withdrawn entirely from the casing or, if desired, it may be raised to a higher level and again locked to the casing by repeating the operations already described.

The construction whereby the pin 16 on sleeve 4 is engagedwith a slot in the upper collarll instead of the lower collar 20, in addition to preventing any possibility of the slip being prematurely set while the device is being lowered through bent or distorted caslng, permlts'the positioning of the collar 17 and spring 18, within the casing engaging springs 21 above the collar 20 instead of below the collar 20. This is advantageous as it permits shortening of the sleeve 4.

I claim:

1. A slip mechanism comprising a sleeve, a slip expander mounted on said sleeve having slip seats thereon extending outwardly, said sleeve extending below said expander, slips mounted on said slip seats, an uppercollar slidably mounted on said sleeve l below said expander, means connecting each slip to said upper collar, a lower collar slida# bly mounted on said sleeve and spaced below said upper collar, a plurality of outwardly bowed casing-engaging springs having their upper and lower ends secured to said upper and lower collars respectively, said upper collar being movable on said sleeve from an uppermost position in which said slips are in set position to a lowermost position in which said slips are in contracted position, a slot in said upper collar opening from the bottom edge thereof and extending upwardly and then downwardly, a pin projecting from said sleeve and engageable with said slot by relative rotation between said upper collar and said sleeve tolock said upper collar into itsv lowermost position, a third collar rigidly connected to said sleeve between said upper and lower collars, a spiral spring surroundin said shaft between said pin and said thir collar, said sprin being compressed between said upper and tliird collar when said pin is rotated into engagement with said slot, and means for rotating said sleeve.

2. In adevice for insertion into a well casing and adapted to be locked to the casing at will, a shaft adapted to be lowered into and turned within a wellcasing, a sleeve slidable on said shaft, a slip expander mounted upon said sleeve, slips longitudinally slidably mounted in slip seats on said expander', said slip seats being inclined upwardly yand outwardly whereby upward movement of said slips relative to sa-id expander expands the slips against the casing, a collar slidably mounted upon said sleeve and linked to said slips, said collar having a slot therein opening from the lower'edge thereof, said slot terminating in a downwardly extending closed lend portion, spring means for frictionally engaging said collar to the well casing, a pin extending from said sleeve engageable with the slot in said collar by rotation of said sleeve with respect to said collar, a second collar fixed to said sleeve below said pin and a spiral spring surrounding said sleeve and positioned above said second collar, said spring being compressed between said two collars when said pin is in the downwardly extending closed end portion ofsaid slot.

Signed atLos Angeles, California, this 19th day of March, 1932. i

NEWTON l/V. WICKERSHAM.

upwardly and 

